Home » Tip of The Day » View MasksView Masks August 28, 2016. Posted in: Tip Of The Day. Hold Alt (Mac: Option) then click on a Layer Mask Thumbnail to toggle between viewing the layer or the layer the mask. « Previous Photoshop Tip: | Next Photoshop Tip: » Sign-up for the PTC Newsletter so that you'll never miss a tutorial!. Your Email Address: